1. Field of the Invention
The present invention relates to an adjustment module, an electronic device with the adjustment module, and an antenna performance adjusting method; more particularly, the present invention relates to an adjustment module, an electronic device with the adjustment module, and an antenna performance adjusting method that adjust the antenna performance via adjusting the capacitance value.
2. Description of the Related Art
As technology develops, the wireless communication system of transmission for the electronic devices is increasingly popular. Therefore, many kinds of antenna modules of different designs are disclosed, such as a ring antenna module, a monopole antenna module, a microstrip antenna module, a plate inverted-F antenna module, a plate antenna module, and a printed antenna module. The antenna modules have different shapes and outward appearance designs according to different frequencies and applications.
However, in the prior art, when a human body or a metal object is closed to the antenna module, the resonance point of the antenna module may be shifted. According to the fundamental of the antenna module, the antenna module has the best performance when its frequency is on the resonance point. Therefore, if the frequency of the antenna module is shifted from the resonance point, the performance of the antenna module decreases.
Please refer to FIG. 1A and FIG. 1B, which are the schematic drawing of a resonance point of an antenna module. FIG. 1A illustrates a schematic drawing of a resonance point of an antenna module of the prior art in the best performance. FIG. 1B illustrates a schematic drawing of a shifting resonance point of an antenna module of the prior art.
According to the fundamental of the antenna module, the resonance point is the best frequency point that allowing the antenna module to achieve the optimum radiation efficiency. As shown in FIG. 1A, when designing the antenna module, the frequency of the resonance point P1 must be adjusted to coordinate the frequency of the wireless signal radiated from the antenna module. When a human body or a metal object is not closed to the antenna module, the frequency of the wireless signal radiated from the antenna module is about 1.95 GHz, and the return loss is about −13 dB; at the moment, the resonance point P1 is not shifted.
However, as shown in FIG. 1B, when the human body or the metal object is closed to the antenna module and the frequency is about 1.95 GHz, the return loss of the antenna module will be about −13 dB, and the resonance point P2 will be shifted obviously. Therefore, the radiation efficiency decreases, and the impedance or the voltage standing wave ratio of the antenna module cannot achieve the best performance. The power of the wireless signal cannot be radiated completely, such that the communication of the antenna module may be poor.
Therefore, there is a need to provide an adjustment module for adjusting the antenna module, an electronic device with an adjustment module, and an antenna performance adjusting method, to solve the problem of the prior art.